Membrane pump

ABSTRACT

A pump comprising a pump body defining a circulation space for circulation of fluid according to a direction of circulation from an entry orifice of the circulation space to an output orifice of the circulation space; a membrane retained in the circulation space substantially parallel to the direction of circulation; and an actuating device adapted to vibrate the membrane in a direction substantially perpendicular to the direction of circulation, wherein the membrane comprises a material or a protective coating having a polymer organic matrix with a Young&#39;s modulus in a range of between 100 MPa and 10 GPa.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119(b) to French Patent Application No. 1454290 entitled “POMPE A MEMBRANE,” by Alban Letailleur, et al., filed May 14, 2014.

FIELD OF THE DISCLOSURE

The present invention relates to a pump for moving fluids, and more particularly to a pump for applications where the fluids to be moved are fluids that are not to be contaminated or damaged, such as biological fluids or high purity fluids, or where the fluids to be moved are aggressive fluids, such as for example those used for the manufacture of semiconductor components.

RELATED ART

To move a solution or a fluid suspension, it is known to use a centrifugal pump comprising an impeller in a pump body. The impeller is typically operated by means of a shaft which passes outwardly from the pump body and which is rotated by an external motor. A drawback of such a centrifugal pump is that there is a risk of contamination or leakage at the bearing through which the drive shaft of the impeller passes. Moreover, the rotation of the impeller in operation generates shear stresses in the fluid, which are disadvantageous in the case of fragile fluids, particularly biological fluids.

Another disadvantage of such a centrifugal pump is that it is not adapted to move aggressive fluids, which tend to destroy the mechanical bearings. Examples of aggressive fluids include suspensions used in CMP (Chemical-Mechanical Planarization) polishing processes which are designed to planarize the surface of semiconductor components. These suspensions can have very fine particles that tend to mechanically attack the bearings.

Industries continue to demand improved pumps.

SUMMARY

It is these disadvantages which the invention is more particularly intended to eliminate, by disclosing a pump that provides effective displacement of fluid, both for small volumes and large volumes of fluid, the pump making it possible to obtain a stable fluid flow rate over time while providing the ability to modulate the fluid flow rate over a wide range of flow rates, the structure of the pump being further adapted to limit the risk of contamination or damage to the fluid to be moved, and enabling use with aggressive fluids.

A pump in accordance with one or more of the embodiments described herein can generally include a pump body which defines a circulation space for circulation of fluid according to a direction of circulation from an entry orifice of the circulation space to an output orifice of the circulation space. The pump can further include a membrane retained in the circulation space substantially parallel to the direction of circulation; and an actuating device adapted to vibrate the membrane, in a direction substantially perpendicular to the direction of circulation. In an embodiment, the membrane may include a protective coating made of a material having a polymer organic matrix with a Young's modulus in a range of between 100 MPa and 10 GPa, such as in a range of between 200 MPa and 2 GPa. Within the meaning of the invention, a “protective coating” is an external part of the membrane intended to be in contact with the fluid during operation of the pump, it being understood that the remainder of the membrane, apart from the protective coating, is configured not to be in contact with the fluid. According to the invention, a fluid is a deformable medium which can be moved, such as a liquid, a gas, a gel, a paste, a powder, a suspension, a dispersion, an emulsion, or a mixture of these. In an embodiment, the membrane is made of a material having a polymer organic matrix with a Young's modulus in a range of between 100 MPa and 10 GPa, such as between 200 MPa and 2 GPa. Throughout this application, numerical values of the Young's modulus are given as measured at 23° C.

In an embodiment, the membrane or the protective coating of the membrane may be integrally made of a polymer organic material having a Young's modulus in a range of between 100 MPa and 10 GPa, such as in a range of between 200 MPa and 2 Gpa. In another embodiment, the membrane or the protective coating of the membrane can be made of a composite material comprising a polymer organic matrix having a Young's modulus in a range of between 100 MPa and 10 GPa, such as in a range of between 200 MPa and 2 GPa, and a reinforcement, in particular a fibrous reinforcement, woven or nonwoven, for example based on glass fibers.

According to certain embodiments of the invention, the pump can be disposed within a container designed to receive at least one fluid, wherein the container is made of flexible material.

A pump with a vibrating membrane as described above may avoid use of mechanical bearings in the pump body, thereby reducing the risk of contamination and leakage. In addition, such a membrane pump can generate little shear stress in the fluid displaced, thereby maintaining integrity of the fluid components while ensuring a high level of fluid displacement. It is possible with such a pump to modulate the fluid flow rate over a wide range, such as for example, from 0.1 L/min to 100 L/min. It is also possible, for a given value of the fluid flow, to obtain a good stability of the fluid flow over time. Another advantage of a pump with a vibrating membrane in accordance with embodiments described herein is that the pump can be self-priming. That is, the pump does not need to be initially filled with the fluid in order to operate. Rather, in practice, the pump can move a certain quantity of air, thus creating a vacuum in the upstream circuit, which allows fluid to flow into the circulation space.

In a particular embodiment, the membrane, or protective coating of the membrane, can include a polymer organic material having a relatively high Young's modulus in a range of between 100 MPa and 10 GPa, such as between 200 MPa and 2 Gpa. To the contrary, elastomers such as silicone or polyurethane elastomers have Young's moduli in a range of between 1 MPa and 10 MPa. It is the merit of the inventors to have found that a membrane made of a material with a polymer organic matrix having a Young's modulus in a range of between 100 MPa and 10 GPa, or a protective coating made of a material with a polymer organic matrix having a Young's modulus in a range of between 100 MPa and 10 GPa, is capable not only of providing a function of fluid propulsion when integrated in a pump with vibrating membrane, but also is able to withstand degradation, especially when the pump is used to move a mechanically aggressive fluid, such as the suspensions used in the CMP polishing processes.

In addition, polymer organic materials having a Young's modulus in a range of between 100 MPa and 10 GPa can also be chemically more stable than silicone or polyurethane elastomers, and less likely to be chemically modified through contact with fluids flowing in the pump.

According to one aspect of the invention, the actuating device can be configured to generate alternately at an end of the membrane situated in the vicinity of the entry orifice of the circulation space, an excitation force which is substantially perpendicular to the direction of circulation.

According to further embodiments of the invention, the membrane can be arranged so that in response to application of an excitation force alternately to one end of the membrane, in a direction substantially perpendicular to the membrane, while the membrane extends parallel to the direction of circulation, at least one undulation of the membrane appears and spreads along the membrane from its end subjected to the excitation force towards another end of the membrane.

In this way, the membrane can constitute a support for displacement of waves from its end which is subjected to the excitation force to its other end. The displacement of these waves can be accompanied by forced damping in the fluid circulation space. Transfer of mechanical energy can thus be established between the membrane and the fluid in the form of a pressure gradient and a fluid flow.

According to a particular embodiment, the excitation of the membrane can be performed at one of the natural frequencies of the membrane, and in particular the first natural frequency of the membrane. In an embodiment, to avoid localized pressure effects in the fluid, the excitation frequency of the membrane can have a value in the range of between 20 Hz and 300 Hz, such as in a range of between 40 Hz and 150 Hz.

At rest, the membrane can be held solely at its periphery. Upon actuation, the surface area of the membrane increases with the formation of waves, resulting in a tension of the membrane in operation, due to the holding at the periphery of the membrane. The periphery of the membrane can be engaged with a peripheral rigid support. The support may exert at the periphery of the membrane efforts to force the return of the membrane in a plane of extension of the support. In the case of discoidal membrane geometry, the support may be a ring, which exerts radiating efforts at the periphery of the membrane.

In an embodiment, a polymer organic matrix of the membrane or of the protective coating of the membrane can be made of a fluoropolymer. In the context of the invention, the term “fluoropolymer” refers to any polymer having in its chain at least one monomer chosen from compounds containing a vinyl group capable of opening to polymerize, or propagating a polymerization reaction, and which contains, directly attached to this vinyl group, at least one fluorine atom, a fluoroalkyl group or a fluoroalkoxy group. Examples of monomers include vinyl fluoride; vinylidene fluoride (VF2); trifluoroethylene (VF3); chlorotrifluoroethylene (CTFE); 1,2-difluoroethylene; tetrafluoroethylene (TFE); hexafluoropropylene (HFP); perfluoro(alkylvinyl)ethers, such as perfluoro(methyl vinyl)ether (PMVE), perfluoro(ethylvinyl)ether (PEVE) and perfluoro(propyl vinyl)ether (PPVE); perfluoro (1,3-dioxole); perfluoro (2,2-dimethyl-1,3-dioxole) (PDD); the product of formula CF₂═CFOCF₂CF(CF₃)OCF₂CF₂X wherein X is SO₂F, CO₂H, CH₂OH, CH₂OCN or CH₂OPO₃H; the product of formula CF₂═CFOCF₂CF₂SO₂F; the product of formula F(CF₂)_(n)CH₂OCF═CF₂ wherein n is 1, 2, 3, 4 or 5; the product of formula R₁CH₂OCF═CF₂ wherein R₁ is hydrogen or F(CF₂)_(z) and z is 1, 2, 3 or 4; the product of formula R₃OCF═CH₂ wherein R₃ is F(CF₂)z- and z is 1, 2, 3 or 4; perfluorobutylethylene (PFBE); 3,3,3-trifluoropropene; 2-trifluoromethyl-3,3,3-trifluoro-1-propene. The fluoropolymer may be a homopolymer or a copolymer, it may also include non-fluorinated monomers such as ethylene. In a more particular embodiment, the fluoropolymer is selected from: fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), polytetrafluoroethylene perfluoropropylvinyl ether (PFA), polytetrafluoroethylene perfluoromethyl vinyl ether (MFA), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylenechlorotrifluoroethylene (ECTFE), polychlorotrifluoroethylene (PCTFE), or a combination thereof.

In an embodiment, the entire pump body can be made of a fluoropolymer, optionally fiber-reinforced, in particular with glass fibers. In another embodiment, each seal of the pump can be made of a fluoropolymer. Fluoropolymers can make it possible to avoid any possibility of contamination, which may be advantageous for high purity applications. Fluoropolymers can also have the advantage of being resistant to chemicals, especially to acids such as sulfuric acid (H₂SO₄), hydrofluoric acid (HF) or phosphoric acid (H₃PO₄) which are used in particular for the manufacture of semiconductors.

According to one aspect of the invention, the pump can comprise a support, which can be connected to the end of the membrane. The support may be of sufficient strength to withstand the excitation force, and at least a projecting part of which passes in a sealed manner towards the exterior of the pump body, the actuating device being configured to act on this projecting part of the support, such as to generate the excitation force at the end of the membrane in an alternating manner.

According to one embodiment, the support can be made of a different polymer material than the material of the membrane or of the protective coating of the membrane. In a particular embodiment, the support can be made of a material selected from polycarbonate, polyphenylene sulfide (PPS), or polypropylene, possibly reinforced by fibers, especially glass fibers. The membrane can then be overmolded on the support, which can save time in assembly of the pump, while improving the adhesion and coupling between the membrane and the support.

According to another embodiment, the support can be made of a same polymer material as the polymer organic matrix of the membrane or of the protective coating of the membrane. The support can then be formed integrally with the membrane, in particular by molding.

According to one aspect of the invention, the entire pump can include, or even consist essentially of, polymer material(s), optionally fiber-reinforced for the parts of the pump having a mechanical function, such as the support. By way of non-limiting example, the pump body may include, or even consist essentially of, polyolefin, polycarbonate, or fluoropolymer such as PFA or PTFE. The support may be made of polycarbonate, polyphenylene sulfide (PPS) or polypropylene, possibly reinforced with glass fibers. The membrane may include, or even consist essentially of, PFA, which has a Young's modulus in a range of between 500 MPa and 600 MPa. Such a pump including, or even consisting essentially of, polymer material(s) can make it possible to limit the manufacturing cost and the weight of the pump. Moreover, there may be no metal part in contact with the fluid or fluids to move, which may be particularly advantageous in the case of displacement of aggressive fluids that tend to attack metal materials or of fluid susceptible to a metallic contamination.

It will be appreciated that several known geometries of membranes are compatible with the invention.

According to one embodiment, the membrane can be in the form of a substantially parallelepiped strip retained in a circulation space which is delimited by two, preferably rigid, walls disposed facing the main surfaces of the membrane. An excitation force substantially perpendicular to the mean plane of the membrane can then be applied to an edge of the membrane which is situated on the side of the entry orifice of the circulation space, such that the deformation waves can be propagated towards an opposite edge of the membrane which is situated on the side of the output orifice of the circulation space.

According to another embodiment, the membrane can have a tubular form, and can be retained in a tubular circulation space with rigid walls. A distribution of symmetric radial excitation forces can then be applied to one end of the tubular membrane which is situated on the side of the entry orifice of the circulation space, such that the deformation waves can be propagated towards the opposite end of the membrane which is situated on the side of the output orifice of the circulation space.

According to yet another embodiment, the membrane can be in the form of a disc, or a portion of a disc, and retained in a circulation space delimited by two, preferably rigid, walls which are disposed facing the main surfaces of the membrane. An excitation force substantially perpendicular to the mean plane of the membrane can then be applied to a first end of the membrane which is situated on the side of the entry orifice of the circulation space, such that the deformation waves can be propagated towards a second end of the membrane which is situated on the side of the output orifice of the circulation space. An advantage of this embodiment with discoidal geometry is that the retention of the membrane in the circulation space can be simplified, since the membrane is retained only at the level of its outer peripheral edge.

According to a first variant of the embodiment with discoidal geometry, the first end of the membrane which is situated on the side of the entry orifice, to which the excitation force is applied, can be a central edge of the membrane, whereas the second end of the membrane which is situated on the side of the output orifice can be an outer peripheral edge of the membrane. This arrangement corresponds to a centrifugal configuration of the pump, wherein the fluid circulates from the centre towards the periphery of the membrane.

According to a second variant of the embodiment with discoidal geometry, the first end of the membrane which is situated on the side of the entry orifice, to which the excitation force is applied, can be an outer peripheral edge of the membrane, whereas the second end of the membrane which is situated on the side of the output orifice can be a central edge of the membrane. This arrangement corresponds to a centripetal configuration of the pump, wherein the fluid circulates from the periphery towards the centre of the membrane. This centripetal configuration can generate an effect of concentration of the energy, from the periphery towards the centre of the circulation space, thus making it possible to obtain pressure gradients which are compatible with those required in industrial applications. This centripetal configuration can also make it possible to work with smaller amplitudes of excitation at the level of the outer peripheral edge of the membrane, and thus to limit the damage to fragile fluids.

In an embodiment, the pump body can include two rigid walls opposite one another, which define between them the circulation space. The membrane can be substantially in the form of a disc and retained in the circulation space parallel to the rigid walls. The, or each, entry orifice can then preferably open into the circulation space in the vicinity of the periphery of the membrane, whereas the, or each, output orifice can open into the circulation space in the vicinity of a central area of the membrane, which corresponds to the centripetal configuration.

Irrespective of the geometry of the membrane, the membrane and/or the support can advantageously comprise orifices, such that the fluid can pass on both sides of the membrane in the circulation space. It can thus be possible to exploit the entire volume of the pump body to transfer the mixing energy. In particular, in the embodiment with discoidal geometry, the membrane and/or the support can comprise at least one peripheral orifice and at least one central orifice.

According to one embodiment, the pump body can comprise a first flange and a second flange forming two, preferably rigid, walls opposite one another which define between them the circulation space, the first flange comprising the entry and output orifices of the circulation space. The second flange can comprise a drainage orifice of the pump.

The transverse cross section of the circulation space of the pump according to the invention, taken perpendicularly to the direction of circulation, can be globally constant, increasing or decreasing from the entry orifice of the circulation space towards the output orifice of the circulation space. In particular, in the case of a membrane with discoidal geometry, the thickness of the circulation space can be globally constant, increasing or decreasing from the periphery of the membrane towards a central area of the membrane. A configuration in which the transverse cross section of the circulation space is globally increasing from the entry orifice towards the output orifice can make it possible to ensure a substantial fluid delivery at the level of the output orifice. A configuration in which the transverse cross section of the circulation space is globally decreasing from the entry orifice towards the output orifice can make it possible to assist the propagation of waves from the end which is subjected to the excitation force towards the other end of the membrane.

According to one aspect of the invention, the actuating device can include at least one linear electromagnetic actuator supplied with an alternating current. As a variant, the actuating device can comprise at least one mechanical actuator, for example a connecting rod-crank actuator, motorized by a variable speed gear motor.

In an embodiment, the pump can include at least one ferromagnetic element, which can be housed in the pump body and which can form a movable part of the actuating device for vibrating the membrane. A winding can then be provided around the pump body so as to induce a displacement of the ferromagnetic element inside the pump body. This configuration may allow for a completely enclosed body pump.

According to one aspect, the pump can include at least one fluid flow sensor at the outlet of the pump, which is connected in feedback with the actuating device, so as to maintain a constant fluid flow.

In an embodiment, a membrane pump according to an embodiment of the invention can make it possible to control the fluid flow rate by adjusting the amplitude and/or the frequency of vibration of the membrane imposed by the actuating device.

A particular embodiment of the invention can also relate to a fluid displacement apparatus comprising a high flow rate distribution pump and a membrane pump as described above, wherein the membrane pump is connected to the outlet of the distribution pump. The provision of a membrane pump according to certain embodiments of the invention at the outlet of a distribution pump can make it possible to obtain a smooth flow of fluid, or to obtain more precision on the amount of fluid delivered. It can also make it possible to act as a proportional valve and to reduce the fluid pressure.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics and advantages of the invention will become apparent from the following description of a pump according to the invention, provided purely by way of example and with reference to the attached drawings in which:

FIG. 1 includes a perspective view with partial cut-out of a pump in accordance with an embodiment;

FIG. 2 includes a transverse cross section according to the planes II-II in FIG. 1;

FIG. 3 includes a perspective view of the membrane of the pump in FIGS. 1 and 2.

DETAILED DESCRIPTION

The following description in combination with the figures is provided to assist in understanding the teachings disclosed herein. The following discussion will focus on specific implementations and embodiments of the teachings. This focus is provided to assist in describing the teachings and should not be interpreted as a limitation on the scope or applicability of the teachings. However, other embodiments can be used based on the teachings as disclosed in this application. Reference to ranges

The terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

Also, the use of “a” or “an” is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one, at least one, or the singular as also including the plural, or vice versa, unless it is clear that it is meant otherwise. For example, when a single item is described herein, more than one item may be used in place of a single item. Similarly, where more than one item is described herein, a single item may be substituted for that more than one item.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent not described herein, many details regarding specific materials and processing acts are conventional and may be found in textbooks and other sources within the fluid pumping arts.

FIGS. 1 and 2 generally include a pump 1 having a pump body 3 which defines in its inner volume a circulation space 4 for fluid flow. A deformable membrane 6 may be contained within the circulation space 4 for the propulsion of fluid. The pump body 3 comprises two flanges, an upper flange 5 and a lower flange 7, connected to each other at their periphery. In the assembled configuration of the pump body 3, a rigid wall 51 of the upper flange 5 is located opposite a rigid wall 71 of the lower flange 7, so that the walls 51 and 71 define therebetween the circulation space 4. As shown in FIG. 1, the circulation space 4 has a disk shape similar to the membrane 6.

The wall 51 of the upper flange 5 may include a peripheral orifice 52 and a central orifice 54, which form, respectively, a fluid entry orifice in the circulation space 4 and a fluid outlet orifice from the circulation space 4. Fluid may circulate in the circulation space 4 in a radial centripetal direction A, from the peripheral entry orifice 52 to the central outlet orifice 54. In practice, tubes (not shown) for fluid supply can be connected to the orifices 52 and 54.

According to embodiments of the invention, at least a portion of the membrane 6 is made of a polymer material having a Young's modulus in a range of between 100 MPa and 10 Gpa. For example, in an embodiment the membrane 6 may include, or consist essentially of, PEA. Flanges 5 and 7 may also be made of a polymer material, such as for example polypropylene. In an embodiment, the membrane 6 and the flanges 5 and 7 may be formed by molding, such as by injection molding.

The membrane 6 has a median plane P and may be maintained under tension in the circulation space 4 parallel to the direction A. An outer peripheral end 61 of the membrane 6 may be fixed to a rigid support 8. The support 8 may include a ring portion 80 and a plurality of peripheral legs 81 distributed circumferentially, projecting from the annular portion 80. The support 8 may be made of a polymer material, such as for example, polycarbonate. The support 8 may be obtained by molding a single piece, such as by injection molding. In an embodiment, the membrane 6 may be assembled with the support 8 by overmolding.

In an embodiment, the membrane 6 may have a central orifice 64 and the support 8 may include a plurality of peripheral orifices 82. Thus, fluid may circulate in the circulation space 4 on both sides of the membrane 6. That is, fluid may circulate both in the volume defined between the membrane 6 and the upper flange 5 and in the volume defined between the membrane 6 and the lower flange 7.

As shown in FIGS. 1 and 2, the peripheral legs 81 of the support 8 may project outwardly from the pump body 3 through holes 78 of the lower flange 7. In an embodiment, the support 8 has six peripheral legs 81 that pass through six holes 78 of the lower flange 7, Seals 2 may be provided in each hole 78. In an embodiment, the seals 2 may be made of a fluoropolymer, such as PTFE, and connected to the legs 81 of the support 8 by any suitable arrangement, including by overmolding, welding, or snap-fitting.

The peripheral legs 81 of the support 8 may be provided to be coupled to an actuating device 9, which in an embodiment comprises a plurality of electromagnetic linear actuators including movable portions 91 that are adapted to be secured with the peripheral legs 81, for example snapped into the interior of peripheral legs 81.

When energized by an alternating current, each actuating device produces a reciprocating translational displacement of a movable part 91, which results from the occurrence of Laplace forces within the actuating device. The moving parts 91 of the actuating devices are then capable of imparting to the support 8 a translational motion in a direction B substantially perpendicular to the median plane P of the membrane 6. Thus, the actuation device 9 is able to generate in an alternative manner, at the outer peripheral end 61 of the membrane 6, an excitation force F substantially perpendicular to the median plane P of the membrane 6.

The material and dimensions of the support 8 may be chosen such that the support 8 has sufficient stiffness to ensure that the excitation force F applied to the peripheral end 61. of the membrane 6 is substantially the same over the entire periphery of the membrane, even if the actuators act discretely at the legs 81.

In an embodiment, to ensure good wave propagation from the peripheral end 61 of the membrane 6 which is subjected to the force F, towards the end of the membrane that defines the central opening 64, the membrane 6 has a thickness e decreasing from its peripheral end 61 to its central orifice 64.

The pump 1 described above which, according to embodiments of the invention, may include a membrane 6. The membrane 6 may be made of PFA, which is a fluoropolymer having a Young's modulus in a range of between 500 MPa and 600 MPa, making it possible to obtain an effective displacement of fluids, both for small and large volumes, and can be used to move mechanically and/or chemically aggressive fluids, such as fluids used for the manufacture of semiconductor components.

By replacing a membrane made of silicone elastomer with a membrane including, or even consisting essentially of, PFA, the fluid flow obtained with the membrane including, or even consisting essentially of, PFA is of the same order as that obtained with the membrane made of silicone elastomer. It has been observed that the decrease in fluid flow of the pump with a membrane including, or even consisting essentially of, PFA relative to the pump with a membrane made of silicone elastomer is, for the same operating frequency of the membrane, within a range of 15% maximum of the fluid flow rate obtained with the membrane of silicone elastomer.

These results can also be obtained when the membrane 6 has a layered structure including, for example, a protective coating made of a material with a polymer organic matrix having a Young's modulus in a range of between 100 MPa and 10 GPa, such as in a range of between 200 MPa and 2 GPa, for example PRA; and at least one inner layer which, in the assembled configuration of the pump, is protected by the protective coating from a fluid flowing in the circulation space 4, where the inner layer may consist of another material than the material of the protective coating.

The inner layer of the membrane may be made of a polymer material having a Young's modulus much lower than 100 MPa, such as a silicone or polyurethane elastomer.

Advantageously, a pump according to certain embodiments of the invention may reduce the shear stresses generated in the circulated fluid, which may avoid damage to the components. A pump according to certain embodiments of the invention is thus applicable to moving all kinds of fluids, including fluids which are fragile or charged with particles, in particular biological or pharmaceutical fluids. A pump according to certain embodiments of the invention is also well suited for mixing of non-Newtonian fluids, the shearing of which is to be controlled, for example for mixing of shear-thinning or shear-thickening fluids, or for mixing of fluids which can clot irreversibly under the shearing effect. In addition, with a pump according to certain embodiments of the invention, the risks of leakage and contamination are limited, thanks to the absence of mechanical bearings associated with a rotating member. A pump according to certain embodiments of the invention also has a reduced size, particularly it is flattened compared to a centrifugal pump thanks to the lower size of the membrane with respect to a turbine.

The invention is not limited to the examples described and illustrated in the Figures.

In particular, as mentioned above, the membrane of a pump according to certain embodiments of the invention can be made of any material with a polymer organic matrix other than PFA, having a Young's modulus in a range of between 100 MPa and 10 GPa, such as in a range of between 200 MPa and 2 GPa, particularly FEP or PTFE. The membrane pump according to certain embodiments of the invention may also have a layered structure as mentioned above, comprising a protective coating made of a material with a polymer organic matrix having a Young's modulus in a range of between 100 MPa and 10 GPa, such as in a range of between 200 MPa and 2 GPa, and a core layer formed by at least one inner layer which may be made of another material than the material constituting the protective coating, especially a polymer material having a Young's modulus much lower than 100 MPa, so as to increase the elasticity of the membrane.

The membrane of the pump may also have a geometry other than discoidal. Inn particular, the membrane may have a blade or tubular geometry. In addition, only one side of the membrane may be used to move the fluid, which would be the case for example in the embodiment described above in the absence of the central opening 64 and/or peripheral holes 82 that allow fluid passage on either side of the membrane. Furthermore, in the above embodiment, the pump may comprise a plurality of entry orifices 52, distributed circumferentially around the periphery of the pump body, and a central output orifice 54. The pump may also include a check valve, for example at the outlet 54, so as to ensure a function of metering pump.

According to another variant of the previous embodiment, the support 8 and the membrane 6 or the protective coating of the membrane 6 can be made of a same material with a polymer organic matrix having a modulus Young in a range of between 100 MPa and 10 GPa, such as in a range of between 200 MPa and 2 GPa. The support may be integral with the membrane, and formed in one piece therewith, particularly by molding. Regardless of the relative configuration of the membrane and the support, in one piece or two separate pieces, the holes for letting the fluid pass on both sides of the membrane in the circulation space, referenced 64 and 82 in the previous embodiment, may be provided either on the membrane or on the support.

In an embodiment, actuating devices other than the linear electromagnetic actuators described above can be used in the context of the invention. In particular, the structure of the electromagnetic actuators can be modified such that a coil is provided around the pump body so as to induce a displacement of the movable part of each actuator inside the pump body. This configuration allows for a completely enclosed pump body without any portion 81 passing towards the exterior of the pump body, which is particularly advantageous for sealing. Alternatively, as already mentioned, the electromagnetic actuators can also be replaced by other types of actuators, such as mechanical actuators.

It is also possible for a single pump to comprise several membranes arranged in parallel so as to undulate together, in the circulation space, under the effect of the excitation force F and arranged to force a flow of fluid through the circulation space from the entry orifice of the circulation space towards the outlet orifice of the circulation space.

Many different aspects and embodiments are possible. Some of those aspects and embodiments are described below. After reading this specification, skilled artisans will appreciate that those aspects and embodiments are illustrative and do not limit the scope of the present invention. Embodiments may be in accordance with any one or more of the items as listed below.

Item 1. A pump comprising a pump body which defines a circulation space for circulation of fluid according to a direction of circulation from an entry orifice of the circulation space to an output orifice of the circulation space, the pump comprising:

-   -   a membrane which is retained in the circulation space         substantially parallel to the direction of circulation,     -   an actuating device which is adapted to vibrate the membrane, in         particular substantially perpendicular to the direction of         circulation,     -   wherein either the membrane comprises a protective coating made         of a material having an polymer organic matrix with a Young's         modulus of between 100 MPa and 10 GPa, preferably between 200         MPa and 2 GPa, or the membrane is made of a material having a         polymer organic matrix with a Young's modulus of between 100 MPa         and 10 GPa, preferably between 200 MPa and 2 GPa.

Item 2. The pump according to item 1, wherein the polymer organic matrix of the membrane or of the protective coating of the membrane is made of a fluoropolymer.

Item 3. The pump according to either one of items 1 or 2, wherein each seal of the pump is made of a fluoropolymer.

Item 4. The pump according to any one of the preceding items, wherein the pump comprises a support, which is connected to an end of the membrane and at least a projecting part of which passes in a sealed manner towards the exterior of the pump body, the actuating device being configured to act on this projecting part of the support, such as to generate in an alternating manner at the end of the membrane an excitation force, preferably substantially perpendicular to the direction of circulation.

Item 5. The pump according to according to item 4, wherein the support is made of a same polymer material as the membrane or the protective coating of the membrane.

Item 6. The pump according to any one of the preceding items, wherein the entire pump is made of polymer material(s), optionally fiber-reinforced.

Item 7. The pump according to any one of the preceding items, wherein the pump body comprises two rigid walls opposite one another, which define between them the circulation space, the membrane being substantially in the form of a disc, and retained in the circulation space substantially parallel to the rigid walls.

Item 8. The pump according to item 7, wherein each entry orifice opens into the circulation space in the vicinity of the periphery of the membrane, whereas each output orifice opens into the circulation space in the vicinity of a central area of the membrane.

Item 9. The pump according to either one of items 7 or 8, wherein the membrane and/or a support connected to an end of the membrane comprise at least one peripheral orifice and at least one central orifice.

Item 10. The pump according to any one of the preceding items, wherein the pump body (3) comprises a first flange (5) and a second flange (7) which form two walls (51, 71) facing one another defining between them the circulation space (4), the first flange (5) having the entry orifice (52) and the output orifice (54).

Item 11. The pump according to any one of the preceding items, wherein the actuating device (9) comprises at least one electromagnetic linear actuator powered by an alternating current.

Item 12. The pump according to any one of the preceding items, comprising at least one ferromagnetic element, which is housed in the pump body and which forms a movable part of the actuating device.

Item 13. The pump according to any one of the preceding items, comprising at least one fluid flow sensor which is connected in feedback with the actuating device.

Item 14. A fluid displacement apparatus comprising a high flow rate distribution pump and a membrane pump according to any one of the preceding items, wherein the membrane pump is connected to the outlet of the distribution pump.

Item 15. A container-mixer comprising:

-   -   a container which is adapted to receive a fluid, wherein the         container is made of flexible material; and     -   a pump according to any one of the preceding items disposed in         the container.

Item 16. A pump comprising:

-   -   a pump body defining a circulation space for circulation of         fluid according to a direction of circulation from an entry         orifice of the circulation space to an output orifice of the         circulation space;     -   a membrane retained in the circulation space substantially         parallel to the direction of circulation; and     -   an actuating device adapted to vibrate the membrane in a         direction substantially perpendicular to the direction of         circulation,     -   wherein the membrane comprises a material or a protective         coating having a polymer organic matrix with a Young's modulus         in a range of between 100 MPa and 10 GPa.

Item 17. The pump according to item 16, wherein the polymer organic matrix of the membrane or of the protective coating of the membrane comprises a fluoropolymer.

Item 18. The pump according to item 16, wherein the pump further comprises at least one seal, and wherein the at least one seal comprises a fluoropolymer.

Item 19. The pump according to item 16, wherein the pump further comprises:

-   -   a support connected to an end of the membrane,     -   wherein a projecting part of the support passes in a sealed         manner towards the exterior of the pump body, and wherein the         actuating device is adapted to act on the projecting part of the         support to generate in an excitation force at the end of the         membrane.

Item 20. The pump according to item 19, wherein the support comprises a polymer material, and wherein the polymer material of the support is the same as a polymer material of the protective coating of the membrane.

Item 21. The pump according to item 19, wherein at least one of the membrane and the support comprises at least one peripheral orifice and at least one central orifice.

Item 22. The pump according to item 16, wherein the pump body comprises a polymer.

Item 23. The pump according to item 22, wherein the polymer is fiber-reinforced.

Item 24. The pump according to item 16, wherein the pump body comprises a first rigid wall and a second rigid wall opposite one another and defining therebetween the circulation space.

Item 25. The pump according to item 24, wherein the membrane comprises a disc, and wherein the membrane is retained in the circulation space substantially parallel to the first and second rigid walls.

Item 26. The pump according to item 16, wherein the entry orifice opens into the circulation space in the vicinity of the periphery of the membrane, and wherein the output orifice opens into the circulation space in the vicinity of a central area of the membrane.

Item 27. The pump according to item 16, wherein the pump body further comprises a first flange defining a first wall and a second flange defining a second wall, wherein the first and second walls define between them the circulation space, and wherein the first flange defines the entry orifice and the output orifice.

Item 28. The pump according to item 16, wherein the actuating device comprises at least one electromagnetic linear actuator powered by an alternating current.

Item 29. The pump according to item 16, further comprising at least one ferromagnetic element coupled to the actuating device.

Item 30. The pump according to item 16, further comprising at least one fluid flow sensor connected with the actuating device.

Item 31. The pump according to item 16, wherein the material or the protective coating has a polymer organic matrix with a Young's modulus in a range of between 200 MPa and 2 GPa.

Item 32. The pump according to item 16, wherein the pump her comprises a check valve disposed at the output orifice.

Item 33. The pump according to item 16, wherein the membrane has a discoidal geometry.

Item 34. A fluid displacement apparatus comprising a high flow rate distribution pump and a membrane pump according to item 16, wherein the membrane pump is connected to an outlet of the distribution pump.

Item 35. A container-mixer comprising:

-   -   a container adapted to receive a fluid, the container comprising         a flexible material; and     -   a pump according to item 16 disposed in the container.

Item 36. A pump comprising:

-   -   a pump body defining a circulation space for circulation of         fluid according to a direction of circulation from an entry         orifice of the circulation space to an output orifice of the         circulation space;     -   a membrane retained in the circulation space substantially         parallel to the direction of circulation; and     -   an actuating device adapted to vibrate the membrane in a         direction substantially perpendicular to the direction of         circulation,     -   wherein the membrane comprises a material or a protective         coating having a polymer organic matrix with a Young's modulus         in a range of between 100 MPa and 10 GPa.

Item 37. The pump according to item 36, wherein the polymer organic matrix of the membrane or of the protective coating of the membrane comprises a fluoropolymer.

Item 38. The pump according to either one of the preceding items, wherein the pump further comprises at least one seal, and wherein the at least one seal comprises a fluoropolymer.

Item 39. The pump according to any one of the preceding items, wherein the pump further comprises:

-   -   a support connected to an end of the membrane,     -   wherein a projecting part of the support passes in a sealed         manner towards the exterior of the pump body, and wherein the         actuating device is adapted to act on the projecting part of the         support to generate in an excitation force at the end of the         membrane.

Item 40. The pump according to according to item 39, wherein the support comprises a polymer material, and wherein the polymer material of the support is the same as a polymer material of the protective coating of the membrane.

Item 41. The pump according to item 39, wherein at least one of the membrane and the support comprises at least one peripheral orifice and at least one central orifice.

Item 42. The pump according to any one of the preceding items, wherein the pump comprises a fiber-reinforced polymer.

Item 43. The pump according to any one of the preceding items, wherein the pump body comprises a first rigid wall and a second rigid wall opposite one another and defining therebetween the circulation space, wherein the membrane comprises a disc, and wherein the membrane is retained in the circulation space substantially parallel to the first and second rigid walls.

Item 44. The pump according to item 43, wherein the entry orifice opens into the circulation space in the vicinity of the periphery of the membrane, and wherein the output orifice opens into the circulation space in the vicinity of a central area of the membrane.

Item 45. The pump according to any one of the preceding items, wherein the pump body further comprises a first flange defining a first wall and a second flange defining a second wall, wherein the first and second walls define between them the circulation space, and wherein the first flange defines the entry orifice and the output orifice.

Item 46. The pump according to any one of the preceding items, wherein the actuating device comprises at least one electromagnetic linear actuator powered by an alternating current.

Item 47. The pump according to any one of the preceding items, further comprising at least one ferromagnetic element coupled to the actuating device.

Item 48. The pump according to any one of the preceding items, further comprising at least one fluid flow sensor connected with the actuating device.

Item 49. A fluid displacement apparatus comprising a high flow rate distribution pump and a membrane pump according to any one of the preceding items, wherein the membrane pump is connected to an outlet of the distribution pump.

Item 50. A container-mixer comprising:

-   -   a container adapted to receive a fluid, the container comprising         a flexible material; and     -   a pump according to any one of the preceding items disposed in         the container.

Note that not all of the features described above are required, that a portion of a specific feature may not be required, and that one or more features may be provided in addition to those described. Still further, the order in which features are described is not necessarily the order in which the features are installed.

Certain features are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombinations.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.

The specification and illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The specification and illustrations are not intended to serve as an exhaustive and comprehensive description of all of the elements and features of apparatus and systems that use the structures or methods described herein. Separate embodiments may also be provided in combination in a single embodiment, and conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Further, reference to values stated in ranges includes each and every value within that range. Many other embodiments may be apparent to skilled artisans only after reading this specification. Other embodiments may be used and derived from the disclosure, such that a structural substitution, logical substitution, or any change may be made without departing from the scope of the disclosure. Accordingly, the disclosure is to be regarded as illustrative rather than restrictive. 

1. A pump comprising: a pump body defining a circulation space for circulation of fluid according to a direction of circulation from an entry orifice of the circulation space to an output orifice of the circulation space; a membrane retained in the circulation space substantially parallel to the direction of circulation; and an actuating device adapted to vibrate the membrane in a direction substantially perpendicular to the direction of circulation, wherein the membrane comprises a material or a protective coating having a polymer organic matrix with a Young's modulus in a range of between 100 MPa and 10 GPa.
 2. The pump according to claim 1, wherein the polymer organic matrix of the membrane or of the protective coating of the membrane comprises a fluoropolymer.
 3. The pump according to claim 1, wherein the pump further comprises at least one seal, and wherein the at least one seal comprises a fluoropolymer.
 4. The pump according to claim 1, wherein the pump further comprises: a support connected to an end of the membrane, wherein a projecting part of the support passes in a sealed manner towards the exterior of the pump body, and wherein the actuating device is adapted to act on the projecting part of the support to generate in an excitation force at the end of the membrane.
 5. The pump according to claim 4, wherein the support comprises a polymer material, and wherein the polymer material of the support is the same as a polymer material of the protective coating of the membrane.
 6. The pump according to claim 4, wherein at least one of the membrane and the support comprises at least one peripheral orifice and at least one central orifice.
 7. The pump according to claim 1, wherein the pump body comprises a polymer.
 8. The pump according to claim 7, wherein the polymer is fiber-reinforced.
 9. The pump according to claim 1, wherein the pump body comprises a first rigid wall and a second rigid wall opposite one another and defining therebetween the circulation space.
 10. The pump according to claim 9, wherein the membrane comprises a disc, and wherein the membrane is retained in the circulation space substantially parallel to the first and second rigid walls.
 11. The pump according to claim 1, wherein the entry orifice opens into the circulation space in the vicinity of the periphery of the membrane, and wherein the output orifice opens into the circulation space in the vicinity of a central area of the membrane.
 12. The pump according to claim 1, wherein the pump body further comprises a first flange defining a first wall and a second flange defining a second wall, wherein the first and second walls define between them the circulation space, and wherein the first flange defines the entry orifice and the output orifice.
 13. The pump according to claim 1, wherein the actuating device comprises at least one electromagnetic linear actuator powered by an alternating current.
 14. The pump according to claim 1, further comprising at least one ferromagnetic element coupled to the actuating device.
 15. The pump according to claim 1, further comprising at least one fluid flow sensor connected with the actuating device.
 16. The pump according to claim 1, wherein the material or the protective coating has a polymer organic matrix with a Young's modulus in a range of between 200 MPa and 2 GPa.
 17. The pump according to claim 1, wherein the pump further comprises a check valve disposed at the output orifice.
 18. The pump according to claim 1, wherein the membrane has a discoidal geometry.
 19. A fluid displacement apparatus comprising a high flow rate distribution pump and a membrane pump according to claim 1, wherein the membrane pump is connected to an outlet of the distribution pump.
 20. A container-mixer comprising: a container adapted to receive a fluid, the container comprising a flexible material; and a pump according to claim 1 disposed in the container. 